1. Field of the Invention
The present invention relates to a disk unit, and more particularly to a magnetic disk unit used for an auxiliary storage of a computing system.
Recently, with the remarkable development of a computing system, more and more reliable, large-capacity and small-sized magnetic disk unit is being demanded.
2. Description of the Related Art
FIG. 1 is a perspective view of a magnetic disk unit of a related art, whose structures are disclosed in U.S. Pat. No. 4,889,237. A plurality of disks rotated by a not-depicted spindle are on the A side, and a positioner for positioning read/write heads is on the B side. Connector 92 leads disk read/write signals to/from not-depicted read/write heads. First printed circuit board (called PCA hereafter) 41, which is for controlling disk read/write operation, is mounted on the upper side of the unit with spacer tubes 44 between and has its connector 95 mated with connector 92. Third PCA 42, which is also for controlling disk read/write operation, is mounted on the rear side and is connected to first PCA 41 via their connectors (not depicted in the figure). Second PCA 43 is for controlling disk read/write and positioning operation according to the commands sent from a not-depicted disk controller via interface connector 35. Second PCA 43 is secured to metal fittings 48, 49 to mount on top of the unit and connected to first PCA 41 via connectors 93, 94 and cables 46. Plates 66 with rubber vibration isolator mounts the unit on a not-depicted cabinet.
A magnetic disk unit with, for example, 8-inch disks is generally predetermined to be up to 216mm(W).times.127mm(H).times.380mm(D) in dimensions to accommodate the unit in a standard cabinet. In the prior structure, however, there was no space for additional disks to increase storage capacity because of the limitation of height. Therefore, a problem is that in spite of an ever-increasing demand for a large-capacity magnetic disk unit, there was no means to satisfy the demand without increasing the size and deteriorating reliability.